the first known instance of an unmanned aircraft system likely used to attempt to deliberately damage energy infrastructure in the united states. >> we have to keep in mind that these physical threats such as this drone attack are very, very real and with the rise of domestic extremism and other national, foreign national types of involvement, you know, i think we can only expect these types of threats to rise. >> reporter: the drone was a simple, very popular consumer model. there were two long pieces of rope attached to it with thick, copper wire. the camera and other identifiers were removed indicating the operator was trying to hide their identity and probably flying it with line of sight near the power sub station. a successful attack could result in widespread regional loss of power. >> some sub stations would probably feed a few hundred people whereas others, you know, it could be thousands or hundreds of thousands of